Leveling of reflector

Abstract

A luminaire (10) includes a substrate (40) having a concave interior surface (44). A reflective surface (42) is supported by the substrate. A leveling layer (48) intermediate the substrate and the reflective surface includes a porcelain enamel. A lamp (12), such as a high intensity discharge lamp, illuminates the reflective surface.

Description

BACKGROUND [0001] The exemplary embodiment relates to the lighting arts. It finds particular application in conjunction with a reflector for a lamp which provides a high beam efficiency and is particularly suited to sporting, roadway, floodlighting, and other applications where the lamp is located at a significant distance from an object to be illuminated. [0002] Luminaires for illuminating roadways and sporting arenas typically include a reflector surface which provides a collimated or highly directional beam of light from a lamp situated adjacent the reflector. A smooth reflector surface is one factor which is desirable for achieving a high beam efficiency. The reflector surface should be as smooth as possible to maximize the amount of specularly reflected light and minimize diffuse reflection. In general, aluminum surfaces only achieve about 60% specular reflection (i.e., about 40% of the reflected light is diffuse) because the sheet aluminum blanks used in forming the reflectors...

AI Technical Summary

Benefits of technology

[0011] An advantage of at least some aspects of the exemplary embodiment is that the proportion of specularly reflected light from a luminaire is increased.

[0012] Another advantage of at least some aspects of the exemplary embodiment is that equivalent illumination of a distant object may be achieved at a lower power consumption.

Problems solved by technology

In general, aluminum surfaces only achieve about 60% specular reflection (i.e., about 40% of the reflected light is diffuse) because the sheet aluminum blanks used in forming the reflectors are not perfectly smooth.

Higher reflectances are generally not possible.

If the polishing is done before the blank is shaped, the reflector can acquire new imperfections in the shaping process.

Moreover, faceted reflectors used in many applications are difficult to polish to high levels of smoothness after shaping.

Additionally, the polishing process tends to be time consuming and thus may not be economically feasible for some lighting applications.

Thus, specular reflection is not significantly improved.

However, due to the size of the reflector, luminaires with glass reflectors tend to be heavy and can fracture relatively easily.

Plastic has also been used for reflectors, but it tends to be limited to low temperature applications.

As a result, the reflector surfaces, particularly those closest to the lamp, tend to become hot during operation.

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